This invention relates to an electrically controlled brake for a vehicle wheel and, more particularly, to a brake of the type in which an electromagnet is mounted on a pin which projects from one side of a brake operating arm. When energized, the electromagnet frictionally engages an armature which rotates with and usually forms part of the drum of the vehicle wheel structure. Such frictional engagement causes the operating arm to pivot and force one or more brake shoes into engagement with the drum to reduce the speed of the wheel.
The electromagnet is capable of floating axially on the mounting pin and usually is urged into light rubbing contact with the armature by a spring which is telescoped over the pin. To prevent the magnet from rotating on the pin, it is customary to secure the magnet to the operating arm with an anti-rotation bracket. One such bracket is disclosed in Penrose U.S. Pat. No. 2,273,065 and is capable of preventing the magnet from rotating on the pin while still allowing the magnet to shift axially into full face-to-face engagement with the armature.